Confilict between nodename and hostname

[amit mehta_2]

Hi,

I was just wondering that what could be the effect of setting differnet "nodename" and "hostname" for an HP box.
i can alter the hostname using,
set_parms hostname
and can change the nodename using,
setuname -n

~amit

[Peter Godron]

Amit,
Not sure why you would want to, but you could also edit the /etc/rc.config.d/netconf file and add NODENAME parameter.

Impact is best explained in "man 1m setuname" "man hostname" and "man 5 hostname"

[amit mehta_2]

Hi Peter,

Are these (i.e. "set_parms hostname" and "setuname" ) just two different interfaces for changing the hostname/nodename ?

~amit

[Peter Godron]

Amit,
two different naming entities.

Hostname is used in a number of locations/programs. Nodename is used mainly by uname -a . It does become clearer, once you have read the man pages ;-)

[Yogeeraj_1]

hi Amit,

it would be like creating two aliases for the same ip address in the /etc/hosts file.

Having different values for nodename and hostname is not something i would recommend, unless you have good reasons for doing so.

If you have observed such an anomaly, you should investigate further and correct it if need be...

kind regards
yogeeraj

[amit mehta_2]

Hi Peter,

My investigation so far:
Excerpt from 1M setuname:
The size of the name and node is limited to UTSLEN-1 characters. <------
UTSLEN is defined in . Only users having appropriate privileges can use this command.

so i looked into /usr/include/sys/utsname.h
and i found following macros defined(rest not mentioned here)
#define __SYS_NMLN_V2 257 <---
#define __SYS_NMLN_V1 9 <---
#define __SNLEN_V2 257
#define __SNLEN_V1 15
# define UTSLEN _SYS_NMLN

#if (_INCLUDE_HPUX_API_LEVEL < 20040821)
#define _SYS_NMLN __SYS_NMLN_V1
#else /* _INCLUDE_HPUX_API_LEVEL >= 20040821 */
#define _SYS_NMLN __SYS_NMLN_V2

Entry in /usr/include/sys/stdsyms.h
#ifdef _HPUX_API_LEVEL
# if _HPUX_API_LEVEL == 20040821
# define _INCLUDE_HPUX_API_LEVEL 20040821
# elif _HPUX_API_LEVEL == 0
# define _INCLUDE_HPUX_API_LEVEL 0
# else /* _HPUX_API_LEVEL != 0 && _HPUX_API_LEVEL != 20040821 */
error "Invalid value for _HPUX_API_LEVEL"
# endif /* _HPUX_API_LEVEL != 0 && _HPUX_API_LEVEL != 20040821 */
#else
# define _INCLUDE_HPUX_API_LEVEL 0


so what i deduce from all above is as follows:
The nodename can be maximum of 8 characters if the macro _HPUX_API_LEVEL is set to
"20040821" else the nodename can be maximum of 256 charcters.Please correct me if i am wrong.

Thanks for pointing me to corrosponding Man pages.

~amit

[Peter Godron]

Hi,
if the hostname length change is what you are after:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=457037
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1020037

[amit mehta_2]

Thanks Peter for giving me pointers.

[amit mehta_2]

Closing the thread as i found what i was looking for.